Panel heaters in the passenger compartment of vehicles are enjoying growing popularity, as they improve the comfort of the passengers and at the same time use electrical energy economically. Existing panel heating concepts mainly use technologies which were originally developed for seat heaters. Seat heaters to improve passenger comfort are well established on the market today. However, panel heaters have some particularities which distinguish them from seat heaters in essential points.
Panel heaters in serial electric wiring are generally implemented with wire heaters, i.e. Joule heating of an electrically heated wire of a defined resistance per unit length. This concept, which is well known from seat heating, drives heating wires up to a relatively high temperature. For this reason cushioning is required towards the side of the decorative covering, in order to homogenize the temperature range across the whole decorative covering and in order to ensure that the stipulated maximum temperature at the decorative covering is not exceeded. The cushioning is also required in order to make the wires invisible from the side of the decorative covering and in order to make it impossible to touch them haptically. Such an integration concept, which requires an additional cushioning of the panel heater, is clearly opposed to slim integration, fast heating behavior and energy-efficient heating and operation.